Lentinus edodes grows wild on oak and chestnut stumps in Japan, China and Korea and is commonly known by the Japanese name Shiitake. After the champignon, it is the most cultivated edible mushroom in the world and is appreciated for its intense flavor. In the East it has been highly valued for several centuries both as a food and as a natural remedy.

– At the end of the sixties the first scientific studies were carried out and some Japanese university researchers in collaboration with the National Institute for Cancer Research in Tokyo obtained beta-glucans and glycoproteins extracts from the mushroom (Lentinan) and subsequently from the mycelium (Lem) . With the first extract the drug Lentinan was produced which after clinical tests was approved in 1976 by the Japanese Ministry of Health. Lentinan is one of the most prescribed anticancer drugs in the world and its properties stimulate the immune system to activate cytokinins, macrophages, T, B and NK lymphocytes. Experiments on guinea pigs in which cancer has been implanted have shown that the mushroom extract inhibits tumor growth between 72 and 92%. Other studies report that Lentinan is able to reverse various neoplastic forms such as sarcoma 180, liver cancer and Erlich’s. However, it has been verified through in vitro tests that the extract appears to have no direct cytotoxic activity against cancer cells, but acts only as a stimulator of the immune system if injected into patients. One study demonstrated the ability of Shiitake extract to prevent oncogenesis and inhibit the formation of metastases. Another study demonstrates the extract’s effectiveness in protecting chromosomes from damage caused by some chemotherapy drugs. Shiitake has also proved useful in case of neoplastic cachexia through the inhibition of the cytokinin responsible for the wasting. The antitumor action of the fungus is optimal when the immune system is fully functional with the state of the pituitary-adrenal axis and the autonomic nervous system efficient. Chemotherapy and radiotherapy which have immunosuppressive action can inhibit the beneficial efficacy of the fungus. Furthermore, the preventive action is considered important: taking this mushroom on a regular and protracted basis has shown considerable effectiveness in reducing the formation and development of the most common degenerative diseases such as tumors and cardiovascular pathologies.

– The extract obtained from the mycelium (Lem) has proved effective against chronic hepatitis B and useful in protecting the liver. Administering the fungus to laboratory mice with chemically damaged livers allowed control of liver enzymes and hindered the formation of fibrosis. Furthermore, antioxidant compounds such as thioproline and mannitol have been identified both in the mycelium and in the carpophore with the deactivating effect of the radicals responsible for the formation of carcinogenic derivatives.

– The eritadenine contained in the mushroom has a cholesterol-lowering action. Regular intake of the mushroom in the daily diet leads to a 20% reduction in cholesterol absorption and at the same time an increase in its good fraction (HDL). Another study in people with hypercholesterolemia indicates that the daily consumption of 10 g of carpophores for two weeks reduces cholesterol levels by a third.

– The Shiitake with the presence of trehalose improves the functionality of the intestine, stimulating the bacterial flora and fighting pathogenic microorganisms. Several compounds of the fungus have demonstrated antibacterial and antifungal action. Metabolites of cultured mycelium inhibited the proliferation of Candida albicans and several strains of bacteria including Streptococcus pyogenes and Staphylococcus aureus. It has also been shown to inhibit the in vitro growth of Streptococcus mutans and S. sobrinus, the bacteria responsible for dental plaque and caries. For its antibacterial action, Shiitake has always been used in the East to prevent or combat colds.

– Shiitake reduces sedimentation in blood vessels and strengthens their connective tissue; it is therefore indicated to prevent arteriosclerosis and the consequent possible damage to the cardiovascular system.

– Shiitake, like Cordyceps sinensis, is useful in stimulating libido in both men and women, increases testosterone production and helps in erectile deficits.

– Contains both vitamin D and ergosterol its precursor. Vitamin D is useful in the prevention of cancer and is essential for the reabsorption of calcium in the kidney, for the intestinal absorption of phosphorus and calcium and for the processes of bone mineralization.